PURPOSE: To realize a high-quality continuous printing action with a little amount of ink for a long time by mounting a first ink vessel and a second ink vessel on an ink storage means, and mounting a level detection means, an ink refilling means, a solvent refilling means, and a vessel connecting means on a regulating means.

CONSTITUTION: When a low level sensor 24 detects the reduction of an ink contained in a first ink vessel 1 to a predetermined low level 27b, a controller 26 closes a first electromagnetic valve 4 and opens a third electromagnetic valve 12. In this manner, an ink supply pump 5 sucks a refilling ink contained in an ink refilling vessel 10 through an ink refilling tube 11 an supplies this ink under pressure to a recording head 2. After that, a printing is carried out using this refilling ink. At this time, by counting the number of ink particle 13 unused for printing, a second vessel 16 can be refilled with an ink by the same amount as that used in the previous printing. After the completion of the ink refilling by the same amount as that used in the printing, a solvent refilling pump 21 is driven to replenish the second ink vessel 16 with a solvent from a solvent refilling vessel 19. The solvent has been fed until the ink level in the second ink vessel 16 is detected by a high level sensor 25.